Re: [PATCH v2 1/1] usb: musb: call pm_runtime_{get,put}_sync before reading vbus registers

From: Ivaylo Dimitrov
Date: Mon Mar 05 2018 - 13:35:26 EST


Hi,

On 5.03.2018 19:38, Bin Liu wrote:
On Wed, Feb 28, 2018 at 01:59:43PM -0800, Tony Lindgren wrote:
* Merlijn Wajer <merlijn@xxxxxxxxxx> [180227 22:29]:
Without pm_runtime_{get,put}_sync calls in place, reading
vbus status via /sys causes the following error:

Unhandled fault: external abort on non-linefetch (0x1028) at 0xfa0ab060
pgd = b333e822
[fa0ab060] *pgd=48011452(bad)

[<c05261b0>] (musb_default_readb) from [<c0525bd0>] (musb_vbus_show+0x58/0xe4)
[<c0525bd0>] (musb_vbus_show) from [<c04c0148>] (dev_attr_show+0x20/0x44)
[<c04c0148>] (dev_attr_show) from [<c0259f74>] (sysfs_kf_seq_show+0x80/0xdc)
[<c0259f74>] (sysfs_kf_seq_show) from [<c0210bac>] (seq_read+0x250/0x448)
[<c0210bac>] (seq_read) from [<c01edb40>] (__vfs_read+0x1c/0x118)
[<c01edb40>] (__vfs_read) from [<c01edccc>] (vfs_read+0x90/0x144)
[<c01edccc>] (vfs_read) from [<c01ee1d0>] (SyS_read+0x3c/0x74)
[<c01ee1d0>] (SyS_read) from [<c0106fe0>] (ret_fast_syscall+0x0/0x54)

Solution was suggested by Tony Lindgren <tony@xxxxxxxxxxx>.

Signed-off-by: Merlijn Wajer <merlijn@xxxxxxxxxx>

Thanks for fixing this. Assuming it passes Bin's tests:

Acked-by: Tony Lindgren <tony@xxxxxxxxxxx>

Applied and sent out. Thanks.


What about stable kernels? Shouldn't this be fixed there as well?

Ivo